Production of polygalacturonides and their use as food additives

ABSTRACT

The invention relates to the use of polygalacturonides as food additives, said polygalacturonides being obtainable via the following process steps: 
     a) a pectinous plant material is subjected to a pectin extraction in aqueous solution; 
     b) the solids are removed from the suspension obtained in step a), consisting of liquid phase including dissolved pectin and solids from the plant material; 
     c) the pectin is precipitated from the liquid phase obtained in step b); 
     d) the pectin obtained in step c) is dissolved in an aqueous solution and cleaved with purified endo-polygalacturonase; 
     e) the polygalacturonides obtained in step d) are processed into a polygalacturonide preparation without using an additional separation step and without hydrolyzing ester groups that are present.

BACKGROUND OF THE INVENTION

The invention relates to polygalacturonides and to the use thereof.Polygalacturonides are oligosaccharides obtained e.g by enzymaticdecomposition of pectins. Pectin has galacturonic acid monomers orgalacturonic acid (methyl)ester monomers as major components. Typically,both monomers are present at the same time, the esterification level ofthe galacturonic acid groups ranging from 0.5% to 70%. The galacturonicacid monomers or ester monomers are α-1,4-linked to each other. Inparticular regions of the pectin molecule, however, rhamnose monomersare inserted in the chain, resulting in a zigzag structure of thepolymer. The rhamnose monomers may have side chains attached theretowhich may be formed of arabans (α-1,5 linkage) and arabinogalactans(linkage: β-1, 3-1, 6-D). The side chains may also include other sugarmonomers. As a supplement, reference is made to the “Flüssiges Obst”Jun. 1997, pp. 301. This citation also describes that the use ofpectinases in juice production for clarification purposes gives rise toundesirable colloids which interfere with further processing and must beremoved or prevented. In natural unfiltrated juices, on the other hand,it is only the pectins rather than the fragments thereof which have anadvantageous influence on the viscosity. It is clear from theseconsiderations that in juice production, for example, the presence ofpectin fragments is undesirable for technical reasons.

In addition to technical aspects, pectins also involve physiologicalaspects. The citation Cerda, J. J., Trans. Am. Clin. Climatol. Assoc.99, 203-213 (1987), describes that pectin from grapefruits plays animportant role in promoting health in consumers. The citation Matsumoto,T. et al, Int. J. Immunopharmacol. 15, 683-693 (1993), describes thatparticular fragments of Bupleuran 2IIc, a pectin-like poly-saccharidefrom the roots of Bupleurum falcatum, might be highly important inpharmaceutical terms. The fragments are obtained by reaction withendo-polygalacturonase (EC 3.2.1.15). Ultimately, the citation Voragen,A. G. J., Trends Food Sci. Technol. 9, 328-335 (1998), providesinformation that non-digestible polysaccharides or oligosaccharides mayhave a number of health-promoting effects on persons consuming same.

Producing oligosaccharides for pharmaceutical purposes from pectinsusing pectinases is known from the citation U.S. Pat. No. 5,683,991. Thepectinases used therein are mixtures of various enzymes whichpossibility also include endo-polygalacturonase (EC 3.2.1.15), so thatcleavage also is effected in the side chain regions. Moreover, the estergroups are hydrolyzed prior to reacting with the pectinases so that, asa result, comparatively small oligosaccharides (2-4 monomers) areobtained.

SUMMARY OF THE INVENTION

Additives in the food industry are to fulfill a variety of functions.Essential functions are in the sector of preparing processed foodstuffs,e.g. with respect to consistency, durability and color appearance.

The invention is based on the technical problem of providing an additivefor foods which would improve the foods in a health-promoting respect,with respect to taste, and optionally with respect to consistency and/orother consumer-related properties.

To solve said technical problem, the invention teaches the use ofpolygalacturonides as additives in goods, said polygalacturonides beingobtainable via the following process steps:

1. a pectinous plant material is subjected to a pectin extraction isaqueous solution;

2. the solids are removed from the suspension obtained in step a),consisting of liquid phase including dissolved pectin and solids fromthe plant material;

3. the pectin is precipitated from the liquid phase obtained in step b);

4. the pectin obtained in step c) is dissolved in an aqueous solutionand cleaved with purified endo-polygalacturonase (EC 3.2.1.15);

5. the polygalacturonides obtained in step d) are processed into apolygalacturonide preparation with using an additional separation stepand without hydrolyzing ester groups that are present.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Within the range of the invention, it is essential that no hydrolysis ofester groups takes place and that, owing to the use of purifiedendo-polygalacturonase (EC 3.2.1.15), only bonds in (naturally)non-esterified galacturonic acid monomer units undergo cleavage. As aresult, a higher amount of comparatively large oligosaccharides, e.g.,with 5-20 monomer units (main and optionally side chains), is obtained.Here, virtually all of the polygalacturonides are saturatedpolygalacturonides, they are less reactive compared to the unsaturatedpolygalacturonides formed by pectin lyase or pectate lyase activity andtherefore do not contribute to non-enzymatic browning and formation ofhydroxymethylfurfural (HMF) from fructose or glucose. The mixture ofvarious oligosaccharide structures thus obtained has distinctadvantages. On the one hand, fragments with largely retained side chainshave a supporting effect on the immune system in physiological terms. Inaddition, the comparatively long oligosaccharides of the inventionassume a roughage effect, as is the case with other long-chain polyersas well. Roughage is important in the prophylaxis and therapy of anumber of diseases such as constipation, diverticulosis, coloncarcinoma, diabetes mellitus, and lipid metabolic diseases. However, thedrawbacks of conventional roughage, namely, binding of essentialnutrients, will be reduced when using oligosaccharides of the inventionranging from 5 to 20 monomer units. Moreover, by virtue of theintestinal bacterial flora as found in organisms, the polygalacturonidesaccording to the invention are converted relatively readily toshort-chain fatty acids such as acetate, butyrate and propionate whichin turn have a positive effect on the intestinal flora and on theintestinal pH value. These fatty acids can be utilized energetically bythe organism (energy content of the basic oligosaccharides: about 2kcal/g), serving particularly mucosa blood circulation as well. Inaddition, the polygalacturonides used according to the invention have anantibacterial and emulsion-stabilizing effect, which is particularlyadvantageous in food-technological terms. This also enables the use asfat substitutes, e.g., in mayonnaises and the like.

The use according to the invention can be effected with a wide varietyof processed foods, such as ready meals, baby food, canned food(including food filled in glassware), such as canned vegetables andcanned fruits, beverages, candy and pastry (including chips and thelike). In addition to plants themselves, vegetable extraction residues,e.g. from juice production, as well as vegetable cell cultures arepossible as pectinous plant material. Plants suitable for use as pectinsource can be exemplified as follows:

Any type of fruits, particularly apples and citrus fruits, vegetables,particularly sugar beets, carrots and tomatoes. The pectin extractioncan be effected in the neutral (pH 6.0-8.0) or acidic range (pH 2.0-3.0;acid: e.g. sulfuric acid, hydrochloric acid, phosphoric acid, citricacid, lactic acid, and/or tartaric acid). Typical process conditions areas follows:

40-120° C., preferably 90-100° C., 1-20 hours, preferably 6-10 hours,optionally multiple repetitions, e.g. twice.

The solids can be removed by (e.g. hydraulic) pressing and/orcentrifugation. Prior to further processing, the resulting solution canbe concentrated using vacuum evaporation and/or ultrafiltration.

The pectin precipitation can be effected in a variety of ways. On theone hand, water-miscible organic (non-ionic) solvents can be used,removing the hydrate cage from the pectin, so as to cause precipitation.For example, acetone and C₁-C₁₀ alkylalcohols are possible, with ethanolbeing preferred from a food-technological view. Alternatively oradditionally, inorganic salts such as sulfates and/or phosphates ofaluminum, copper and/or calcium can be employed.

Preferably, step d) is performed using a pH of from 1.4 to 8.2, morepreferably from 3.5 to 5.0. The endo-polygalacturonase (EC 3.2.1.15)which is used can be recovered from plants or from microorganismsoccurring therein, e.g., cotton/Aspergillus flavus/Aspergillusparasiticus, rye/Claviceps purpurea, maize/Cochlioboluscarbonum/Fusarium monilifonne, American walnut/Cryphonectria parasitica,tomato/Fusarium oxysporum/Ralstonia (Pseudonomas) solanacearum,rice/Rhizoctonia solani, grass/Sclerotinia borealis, sunflower/Sclerotinia sclerotiorum, and apple/Stereum pureum,carrot/Ertwinia carotorova or Burkholderia (Pseudomonas) cepacia, orfrom microorganisms genetically engineered so as to produce awell-defined endo-polygalacturonase (EC 3.2.1.15). The latter ispreferred for its comparatively easy purification. In addition towell-known genes of the above-exemplified microorganisms, well-knowncDNAs or cDNAs from plants themselves which encode well-known enzymestructures are possible for recombinant operations. Examples ofwell-known plant cDNAs are those from Arabidopsis thaliana, Perseaamericanus and Prunus persica. Examples of well-knownendo-polygalacturonase (EC 3.2.1.15) of plants are those fromLycopersicon esculentum, Musa acuminata, Gossypium barbadense, Gossypiumhirsutum, Cucumus sativus, Phaseolus vulgaris, Citrus limon, Mangifersindica, Cucumis melo, Passiflora edulis, Prunus persica, Pyrus communis,Rubus idaeus, and Fragaria ananassa. It is preferred to use one or moreendo-polygalacturonase (EC 3.2.1.15) selected from theendo-polygalacturonase (EC 3.2.1.15) which can be obtained fromorganisms of the group consisting of Aspergillus carbonarius,Aspergillus niger, Aspergillus oryzae, Aspergillus tubingensis,Aspergillus ustus, Kluyveromyces marxianus, Neurospora crassa,Penicillium frequentans, and Saccharomyces cerevisiae SCPP,Lactobacillus casei, Lactobacillus plantarum, Lactococcus lactis,Bacteroides thetaiotaomicron, Piromonas communis, Neocalimastixpatriciarum, or from other microorganisms modified with DNA sequences ofthe above organisms which encode the endo-polygalacturonase (EC3.2.1.15). The purification can be effected using e.g. the gelfiltration technology which is well-known to those skilled in the art.The amount of endo-polygalacturonase (EC 3.2.1.15) employed in step d)advantageously ranges from 10 to 1000, preferably from 20 to 400 U/gpectin. Determination of the activity is effected using the followingmethod:

10 mg/l polygalacturonic acid (e.g. Sigma P 7276, according to theproduct specification valid on Mar. 01, 2000) is dissolved in substratebuffer (2 mM citric acid solution, 1 mM CaCl₂) and added with definedquantity of enzyme solution. Incubation is effected for 15 min at 23° C.The reaction then is stopped by adding an equal volume of 4.4 mM2-hydroxy-3, 5-dinitrobenzoic acid solution, boiling for 5 min, andcooling to 0° C. Eventually, the absorption at 540 nm is detected, andthe conversion is determined from these values against a standard curvein the usual manner. One unit is the conversion of 1 μM of galacturonicacid per minute.

In a particularly preferred embodiment of the invention, theendo-polygalacturonase (EC 3.2.1.15) is immobilized by inclusion inenzyme membrane reactors, e.g. flat membrane or hollow fiber membranereactors, or binding to a conventionally prepared support material canbe effected in an absorptive, ionic chelating, covalent way, or bycrosslinking.

The immobilization allows to make sure that the final product isvirtually free of endo-polygalacturonase (EC 3.2.1.15) and, in fact,without an extra separation. In this way, interfering reactions due tootherwise possible entraining of the employed endo-polygalacturonase (EC3.2.1.15) with pectins possibility included in the food is virtuallyexcluded. In particular, this is advantageous because undesirabledecomposition of pectins included in the foods might have an unfavorableeffect on the consistency of the foods, e.g. the viscosity thereof.Moreover, the endo-polygalacturonase (EC 3.2.1.15) consumption iscomparatively low.

The reaction with endo-polygalacturonase (EC 3.2.1.15) in step d)preferably is effected at 4 to 80° C., more preferably 30 to 70° Cm, for2 to 300 min, preferably 45 to 150 min. The operations can be performedin a continuous or discontinuous (batchwise) fashion. As to thecontinuous process, the above-mentioned time period relates to theaverage residence time in a reaction volume containingendo-polygalacturonase (EC 3.2.1.15).

The polygalacturonides according to the invention are employed atconcentrations of from 0.01 to 1.0 g/kg food, preferably from 0.1 to 0.5g/kg food. The concentration should be adjusted with regard to normalhuman food consumption so as to maintain doses of from 0.5 to 50 mg,preferably from 1 to 25 mg per kg body weight per day.

With reference to the examples which merely represent embodiments, theinvention will be illustrated in more detail below.

EXAMPLE 1

Isolation and purification of a endo-polygalacturonase (EC 3.2.1.15)from tomatoes.

Tomatoes, 1 kg, are homogenized in 1 liter (1) of water, and thesuspension obtained is adjusted to pH 3.0. The solids (cell residues)are removed by centrifugation (10,000 g, 20 min) and washed in water.The pellets are taken up to 50 mM sodium acetate/1.25 mM NaCl (ph 6.0)at 4° C. for 1 hour. Proteins are precipitated by means of 70% ammoniumsulfate saturation and removed by centrifuging (10,000 g, 20 min). Theprotein pellet is dissolved in 0.125 M sodium acetate (pH 6.0) anddialyzed against said buffer. The proteins then are separated on a CMSepharose column in a 2-stage gradient (0.45 M sodium acetate, pH 6.0,and 1.0 M sodium acetate, pH 6.0). The endo-polygalacturonase (EC3.2.1.15) elutes with the first stage.

EXAMPLE 2

Preparation and purification of a endo-polygalacturonase (EC 3.2.1.15)from genetically engineered microorganisms.

Yeast (Saccharomyces cerevisiae) is transformed using an expressionplasmid including cDNA of the Aspergillus niger endo-polygalacturonase(EC 3.2.1.15) gene under yeast ADH1 promoter control.

The plasmid still includes the yeast replication origin and yeastselection marker (e.g. LEU2 gene). The yeast strain obtained ispre-grown in nutrient medium (minimal medium) and cultured in afermentation process wherein the endo-polygalacturonase (EC 3.2.1.15) isdischarged into the nutrient medium.

The yeast cells are harvested from 500 ml of medium (centrifuging: 6000g, 10 min).

The clear medium supernatant is transferred on a carboxymethylcellulosecation exchange column and equilibrated with 10 mM sodium acetate (pH4.0). The proteins are eluted using a linear gradient of from 1 to 1.5 MNaCl in 10 mM sodium acetate (pH 4.0). Fractions including. pureendo-polygalacturonase (EC 3.2.1.15) elute between 0.6 and 0.75 M NaCl.

EXAMPLE 3

Isolation and Purification of a Polygalacturonase From a CommerciallyAvailable Pectinase

50 g of a commercially available enzyme mixture is dissolved in 200 mlof 0.02 M sodium acetate (pH 3.6) with stirring for 3 hours. Solidcomponents are removed by centrifuging (25,000 g, 10 min). The solutionthen is desalted using a Sephadex g 50 column. The proteins aretransferred on an alginate column (matrix by crosslinking alginate withepichlorohydrin) and equilibrated with 0.02 M sodium acetate (pH 3.6).Elution is effected using 0.1 M sodium acetate, pH 4.2, then pH 5.6, andsubsequently using a linear NaCl gradient of from 0 to 1 M in acetatebuffer, pH 5.6.

The endo-polygalacturonase (EC 3.2.1.15) is eluted in the salt gradient.

EXAMPLE 4

Immobilization of a Polygalacturonase

3 g of a particulate carrier, e.g. silicate or glass carrier derivatizedwith surface-bound NH₂ groups (Solvay Enzymes, Hanover), is suspended in20 ml of 0.01 M Sørensen phosphate buffer (pH 7.0) and degassed. 0.2 g,i.e. 1000 U of endo-polygalacturonase (EC 3.2.1.15) from Example 3 isdissolved in 5 ml buffer, pH 7.0, and added to the carrier suspension.With stirring, the decline of the extinction at 280 nm is monitored forabout 30 to 60 min. The solution is removed, followed by washing 5 timeswith water, and coupling is effected by adding 10 ml of glutaricdialdehyde solution (5%) and stirring for 30 min. Thereafter, this iswashed 5 times in water, 1 hour, followed by washing 3 times with buffer(pH 5.0). Finally, this is suspended in 50 ml of buffer, pH 5.0, toobtain covalently immobilized endo-polygalacturonase (EC 3.2.1.15).

EXAMPLE 5

Preparation of Oligogalacturonides from Bupleurum falcatum

Washed roots of Bupleurum falcatum, 1 kg, are chopped mechanically andsubjected to an extraction process step using 30 kg of deionized water.The extraction is performed twice for 8 hours at 98° C. and atmosphericpressure. Following cooling below 60° C., the suspension obtained iscentrifuged (4000 g for 10 min.) to remove solids. The clear supernatantobtained is concentrated to {fraction (1/10)} of the original volumeusing vacuum evaporation.

The pectin is precipitated by adding 4 parts by weight of ethanol (96%)per part by weight of solution and separated from the liquid phase bycentrifuging (10,000 g for 10 min) at 4° C., optionally with subsequentdialysis. The pectin obtained then is dissolved in a 0.1 M sodiumacetate buffer (pH 4.2) and reacted with 300 U/g pectin employed ofendo-polygalacturonase (EC 3.2.1.15)(from Aspergillus japonicus,available from the Sigma Company under the product designation P 3304,according to the product specifications valid on Mar. 01, 2000) for 4hours at 37° C., said reaction being done batchwise. Thepolygalacturonides obtained are recovered in solid form by evaporatingthe water.

EXAMPLE 6

Preparation of Galacturonides from Beet Pressed Chips

Beet pressed chips, 1 kg, from the beet-processing industry areextracted in 15 kg of an acidic aqueous solution (phosphoric acid, pH1.5) for 1 hour at 90° C., Following cooling to 20° C., the solid phaseis removed by hydraulic pressing and optional filtration. Using vacuumevaporation, this is concentrated to {fraction (1/10)} the volume of theliquid phase. The pectin is precipitated by adding 2 parts by weight ofisopropanol per part by weight of concentrate. Following centrifugation(10,000 g, 10 min) and drying (70° C., 1 hour), the enzymatic hydrolysisis accomplished by adding an aqueous solution of 5 g/kg water (adjustedto pH 4.0) of pectin extract with 20 U/g pectin ofendo-polygalacturonase (EC 3.2.1.15) from Example 1 and performing thereaction for 60 min at 60° C. The polygalacturonides obtained arerecovered in solid form by evaporating the water.

EXAMPLE 7

Production of Baby Food Containing Polygalacturonides

A ready-to-eat baby food processed as a mash is mixed homogeneously with0.1 g/kg mash of polygalacturonides from Example 6, and the mash then ispackaged in a ready-for-sale fashion. The mash proves to beemulsion-stabilized.

EXAMPLE 8

Production of a Soft Drink Containing Polygalacturonides

A tea is prepared from green tea leaves in the usual manner. Followingcooling, 1 g/kg beverage of polygalacturonides from Example 5 are addedto the tea to form a solution. The ready-to-bottle product thus obtainedhas an agreeably sour taste.

EXAMPLE 9

Immobilization by Crosslinking

500 mg of endo-polygalacturonase (EC 3.2.1.15) is dissolved in 15 ml ofdistilled water. With stirring in an ice bath, 30 ml of ice 3-coldacetone is slowly added, followed by addition of 2 ml of a 25% glutaricdialdehyde solution. Thereafter, this is agitated for 60 min at 30° C.and subsequently centrifuged. The supernatant is discarded, and theresidue is stirred up with 40 ml of distilled water and homogenizedusing an Ultra Turrax. Following centrifugation and discarding of thesupernatant, the residue is washed once more with 40 ml of distilledwater. The crosslinked preparation obtained is suspended to make 100 ml.

EXAMPLE 10

Fractionation of Polygalacturonides

1.5 g of the polygalacturonides from Example 6 are dissolved in 15 ml ofdistilled water. The polygalacturonides are separated usingchromatography. The solution is transferred on an anion exchange column(2.5/40 cm, BioRad AGMP 1) 150 ml in volume, equilibrated with eluent(0.2 M sodium formate buffer, pH 4.7). The polygalacturonides are elutedusing a linear gradient between 0.2 and 0.7 M sodium formate buffer (pH4.7).

The composition of the individual fractions is subsequently analyzedusing thin layer chromatography (TLC). The fractions are transferred onthe stationary phase, Silicagel 60 (Merck); a mixture of one partethanol and one part acetate (25 mM) is used as mobile phase. Thedevelopment is performed at 35° C. The individual polygalacturonides aremade visible by spraying with a reagent (200 mg of naphthalene-1,3-diolin 50 ml of methanol and 50 ml of 20% (g/g) sulfuric acid). Fractions ofequal composition are pooled, and the polygalacturonides contained inthese fractions are precipitated with double the volume of acetone andseparated from the acetone after centrifugation (6000 g, 10 min) toobtain polygalacturonides of well-defined size.

What is claimed is:
 1. A method of making a polygalacturonidepreparation useful as a food additive, said method comprising thefollowing steps: a) subjecting pectinous plant material to a pectinextraction in an aqueous medium to obtain a suspension comprising of aliquid phase comprising dissolved pectin and solids from the plantmaterial; b) removing the solids from the suspension to obtain a liquidmaterial; c) precipitating the pectin from the liquid material to obtaina pectin precipitate; d) dissolving the pectin precipitate in an aqueousmedium and cleaving the dissolved pectin with purifiedendo-polygalacturonase to obtain polygalacturonides; and thereafter e)processing the polygalacturonides obtained in step d) into thepolygalacturonide preparation without using an additional separationstep and without hydrolyzing any ester groups that are present.
 2. Themethod according to claim 1, wherein the pectin is precipitated byadding C₁-C₁₀ alkylalcohols and/or inorganic salts.
 3. The methodaccording to claim 1, wherein step d) is conducted at a pH of from 1.4to 8.2.
 4. The method according to claim 1, wherein theendo-polygalacturonase is purified using gel filtration.
 5. The methodaccording to claim 1, wherein from 10 to 1000 units ofendo-polygalacturonase per gram of pectin is used in step d).
 6. Themethod according to claim 1, wherein the endo-polygalacturonase isimmobilized.
 7. The method according to claim 1, wherein the dissolvedpectin is cleaved with the purified endo-polygalacturonase in step d) at4 to 80° C. for 2 to 300 min.
 8. The method according to claim 3,wherein step d) is conducted at a pH of from 3.5 to 5.0.
 9. The methodaccording to claim 5, wherein from 20 to 400 units ofendo-polygalacturonase per gram of pectin is used in step d).
 10. Themethod according to claim 7, wherein the dissolved pectin is cleavedwith the purified endo-polygalacturonase in step d) at 30 to 70° C. 11.The method according to claim 10, wherein the dissolved pectin iscleaved with the purified endo-polygalacturonase in step d) for 45 to150 min.
 12. The method according to claim 2, wherein step d) isconducted at a pH of from 1.4 to 8.2.
 13. The method according to claim2, wherein the endo-polygalacturonase is purified using gel filtration.14. The method according to claim 2, wherein from 10 to 1000 units ofendo-polygalacturonase per gram of pectin is used in step d).
 15. Themethod according to claim 2, wherein the endo-polygalacturonase isimmobilized.
 16. The method according to claim 2, wherein the dissolvedpectin is cleaved with the purified endo-polygalacturonase in step d) at4 to 80° C. for 2 to 300 min.
 17. The method according to claim 3,wherein the endo-polygalacturonase is purified using gel filtration. 18.The method according to claim 3, wherein from 10 to 1000 units ofendo-polygalacturonase per gram of pectin is used in step d).
 19. Themethod according to claim 3, wherein the endo-polygalacturonase isimmobilized.
 20. The method according to claim 3, wherein the dissolvedpectin is cleaved with the purified endo-polygalacturonase in step d) at4 to 80° C. for 2 to 300 min.
 21. The method according to claim 4,wherein from 10 to 1000 units of endo-polygalacturonase per gram ofpectin is used in step d).
 22. The method according to claim 4, whereinthe endo-polygalacturonase is immobilized.
 23. The method according toclaim 4, wherein the dissolved pectin is cleaved with the purifiedendo-polygalacturonase in step d) at 4 to 80° C. for 2 to 300 min. 24.The method according to claim 5, wherein the endo-polygalacturonase isimmobilized.
 25. The method according to claim 5, wherein the dissolvedpectin is cleaved with the purified endo-polygalacturonase in step d) at4 to 80° C. for 2 to 300 min.
 26. The method according to claim 6,wherein the dissolved pectin is cleaved with the purifiedendo-polygalacturonase in step d) at 4 to 80° C. for 2 to 300 min.
 27. Acomposition comprising a food and a health promoting agent consistingessentially of polygalacturonides obtained by the process of claim 1.28. The composition according to claim 27, wherein the food is beverage.29. The composition according to claim 27, wherein the food is babyfood.
 30. The composition according to claim 27, wherein the food iscanned food.
 31. The composition according to claim 27, wherein thepolygalacturonides improve the taste of the food.